This invention relates generally optical fibers and more particularly to devices and methods of use for protecting the spliced, e.g., fused, ends of a pair of optical fibers.
Optical fibers are widely employed and are optical wave-guides with an inner glass core having a refractive index which exceeds that of a surrounding cladding layer and are capable of conducting an optical ray by means of total internal reflection or guiding.
Mechanical devices are currently available for providing mechanical and environmental protection to a set or sets of optical fibers which have been stripped of their cladding, cleaved, and fused into a continuous length. Two types of mechanical devices are currently available. One type of device comprises an elongated heat shrinkable plastic tube, an elongated hot-melt adhesive tube, and an elongated strengthening member. The hot-melt adhesive tube and the strengthening member are disposed side-by-side within the plastic tube. Prior to making the splice between the fibers, i.e., fusing the cleaved fiber ends, the heat-shrink tube is threaded onto one of the fibers remote from the splice region, with the fiber extending through the hot melt adhesive tube. After the fiber ends are fused the heat-shrink tube is moved into position over the splice joint so that the splice joint is within the hot melt adhesive tube. The heat-shrink tube is then exposed to localized heat to cause the hot-melt adhesive to flow around the splice and the heat shrink tube to shrink into contact therewith to intimately encircle the fused joint and thereby protect it.
Another type of mechanical device is the so-called clam shell device. This device comprises a pair of plates that are hinged together along one edge thereof. Either or both of the plates may be provided with a pair of axially aligned recesses or grooves in its inner surface to receive the buffers of the spliced optical fibers. The inner surface of each plate includes a thin adhesive layer thereon. Thus, after the fused splice is located so that its buffers are within the pair of aligned recesses the two plates are closed together, i.e., pivoted toward each other, to cause the adhesive on their inner surfaces to engage each other, thus holding the device closed to enclose the fused joint and thereby protect it.
While the prior art splice protectors are generally suitable for their intended purposes, they nevertheless suffer from one or more of the following disadvantages, complexity of use, inability to be accommodate various sizes of optical fibers with a single protector, long-term reliability.